A phase II trial of fractionated irinotecan plus carboplatin for previously untreated extensive-disease small cell lung cancer

Purpose: Irinotecan plus cisplatin has been previously documented to be effective in the treatment of extensive-disease small cell lung cancer (ED-SCLC). This study was undertaken to investigate the efficacy and feasibility of combination chemotherapy of irinotecan and carboplatin in previously untreated ED-SCLC. Patients and methods: From December 2002 to October 2005, 39 patients with previously untreated ED-SCLC were enrolled. Patients were treated with irinotecan (50 mg/m² IV on days 1, 8, and 15) and carboplatin (target AUC = 5 IV on day 1) every 4 weeks for up to six cycles. Results: Thirty-four patients (87.2%) were male and the median age was 65 years. ECOG performance status was 0-1 in 20 (51.3%) patients and 2 in 19 (48.7%) patients. The median number of chemotherapy cycles was six (range: 1-6 cycles). Thirty-five patients were assessable for response evaluation. The overall response rate was 69.2% (1 CR, 26 PR) under the intent-to-treat analysis. After a median follow-up of 22.7 months, the median time to progression was 6.4 months (95% confidence interval [CI]: 5.7-7.1 months) and median overall survival was 11.0 months (95% CI: 9.9-12.0 months). The estimated 1-year survival rate was 42.5%. In terms of toxicities, Grade 3/4 neutropenia and thrombocytopenia occurred in eight (25.6%) and five (15.4%) patients, respectively. Grade 3/4 non-hematologic toxicities included diarrhea (10.3%), anorexia (7.7%), infection (10.3%), and neutropenic fever (12.8%). There was one treatment-related death due to superimposed infection on the broncho-pleural fistula. Conclusion: The combination chemotherapy of irinotecan and carboplatin was effective and tolerable in previously untreated ED-SCLC patients.